发表机构
Institute of Solid State Physics, TU Wien; School of Physics, Northwest University（维也纳工业大学固体物理研究所; 西北大学物理学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过DFT+DMFT计算和ARPES模拟，揭示无限层镍酸盐A-pocket的强杂化轨道本质，并强调光电子矩阵元对解释光谱特征的关键作用。
AI 中文摘要
无限层镍酸盐中所谓的$A$-pocket的轨道特征仍存在争议。我们利用密度泛函理论结合动力学平均场理论研究了块体NdNiO$_2$，并确定$A$-pocket是一种强杂化态，具有显著的间隙-$s$、Nd-$d_{xy}$和Ni-$d_{xz/yz}$贡献。我们的角分辨光电子能谱模拟再现了实验测量的主要偏振依赖特征。移除间隙-$s$矩阵元会导致与测量的费米面图明显不一致，尽管间隙-$s$贡献并不占主导。相反，抑制Nd-$d_{xy}$或Ni-$d_{xz/yz}$矩阵元则几乎不改变费米面图，因为这些在区域角落处很小。更广泛地说，我们的结果表明，要确定无限层镍酸盐中光谱特征的微观起源，必须同时考虑轨道杂化和光电子矩阵元。
英文摘要
The orbital character of the so-called $A$-pocket in infinite-layer nickelates remains under debate. We investigate bulk NdNiO$_2$ using density-functional theory combined with dynamical mean-field theory and identify the $A$-pocket as a strongly hybridized state with substantial interstitial-$s$, Nd-$d_{xy}$ and Ni-d_${xz/yz}$ contributions. Our angle-resolved photoemission spectroscopy simulations reproduce the main polarization-dependent features measured experimentally. Removing the interstitial-$s$ matrix element leads to a clear disagreement with the measured Fermi surface maps, even though the interstitial-$s$ contribution is not dominant. Suppressing instead the Nd-d$_{xy}$ or Ni-$_{dxz/yz}$ matrix elements leaves the maps almost unchanged, because these are small at the zone corner. More generally, our results demonstrate that assigning the microscopic origin of spectral features in infinite-layer nickelates requires treating orbital hybridizations and photoemission matrix elements together.
